feat(dependencies): add rxdart package and improve string extension methods for better handling of empty strings and gender parsing

test/features/settings/models/oauth_attach_request_test.dart

@@ -0,0 +1,32 @@
+import 'package:eatvio_app/features/settings/models/oauth_attach_request.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('OAuthAttachRequest', () {
+    test('создает OAuthAttachRequest с правильными значениями', () {
+      const model = OAuthAttachRequest(
+        provider: 'yandex',
+        clientId: 'client-123',
+        accessToken: 'access-token',
+        refreshToken: 'refresh-token',
+      );
+
+      expect(model.provider, 'yandex');
+      expect(model.clientId, 'client-123');
+      expect(model.accessToken, 'access-token');
+      expect(model.refreshToken, 'refresh-token');
+    });
+
+    test('создает OAuthAttachRequest без clientId', () {
+      const model = OAuthAttachRequest(
+        provider: 'yandex',
+        clientId: null,
+        accessToken: 'access-token',
+        refreshToken: 'refresh-token',
+      );
+
+      expect(model.clientId, isNull);
+    });
+  });
+}
+